@rayyamhk/matrix/lib/core/operations/pow.js

A professional, comprehensive and high-performance library for you to manipulate matrices.

"use strict";

var _require = require('../../Error'),
    INVALID_MATRIX = _require.INVALID_MATRIX,
    INVALID_SQUARE_MATRIX = _require.INVALID_SQUARE_MATRIX,
    INVALID_EXPONENT = _require.INVALID_EXPONENT;
/**
 * Calculates the power of any square matrix.
 * The algorithm is implemented recursively.
 * @memberof Matrix
 * @static
 * @param {Matrix} A - Any square Matrix
 * @param {number} exponent - Any Non-negative integer
 * @returns {Matrix} The power of A
 */


function pow(A, exponent) {
  if (!(A instanceof this)) {
    throw new Error(INVALID_MATRIX);
  }

  if (!A.isSquare()) {
    throw new Error(INVALID_SQUARE_MATRIX);
  }

  if (!Number.isInteger(exponent) || exponent < 0) {
    throw new Error(INVALID_EXPONENT);
  }

  var size = A.size()[0];

  if (exponent === 0) {
    return this.identity(size);
  }

  if (exponent === 1) {
    return this.clone(A);
  }

  if (exponent % 2 === 0) {
    var _temp = this.pow(A, exponent / 2);

    return this.multiply(_temp, _temp);
  }

  var temp = this.pow(A, (exponent - 1) / 2);
  return this.multiply(this.multiply(temp, temp), A);
}

;
module.exports = pow;